I have an iPhone 4S from Sprint on iOS 5.1 (not 5.1.1) that I want to unlock to use GSM and use with SIM cards. I can't seem to jailbreak it because it's on 5.1 and redsn0w grays out the jailbreak button when I connect the iPhone 4S. It seems I can't upgrade to 5.1.1 because Apple doesn't sign 5.1.1 anymore. I want to use Geavey Ultra S CDMA but that requires jailbreaking for the CDMA phones. So, what options do I have to get the iPhone 4S unlocked and working? I don't want to upgrade to iOS 6 since there's only tethered jailbreak but the iPhone is going to be a present for a friend traveling and not always with an access to a computer. Any ideas? Thanks.